In current electronic circuits, the use of increasingly higher speed switching signals has necessitated control of impedance for signal transmission. In an attempt to provide an impedance matched connector, a coaxial type connector as described in U.S. Pat. No. 4,451,107, was devised. Although some of the above mentioned problems were solved, other serious problems arose. At high speed transmission, the right angle of the terminals causes reflection of the signals limiting the effectiveness of the connector at high speed transmission.
The manufacturing of the connector described in U.S. Pat. No. 4,451,107 is also made impractical by the manufacturing process of die casting the metal housing, injection molding of nylon sleeve, casting the terminals through the nylon sleeves in the housing. This process of manufacturing is very difficult to control and can lead to faulty connections. Therefore, the configuration of the invention of the above cited reference is impractical for many reasons.
In another attempt to design an impedance control connector, as shown in U.S. Pat. No. 4,836,791, a mother-daughter board connector is disclosed and shows a motherboard connector 10 and a right angle connector or plug connector 8 which is interconnectable to the motherboard 10. The motherboard 10 includes a plurality of tab assemblies 20. A right angled connector 8 includes insulative housing 22 having a plurality of apertures 12 therethrough. In order to control the impedance of the terminals in a right angled connector, since the signal path distances must differ, a dielectric coil spring 56 or dielectric member 49 is placed over the terminals 18. The selection of the material and configuration of the coil springs 56 and dielectric 49 can alter the speed at which the signals propagate through the terminals. Since the length of the terminals vary, the dielectric constant for the shorter terminals is higher, slowing the signals down somewhat, whereas the longer terminals have a lower dielectric constant to increase the speed of the signal relative to the shorter signals. While in theory the above mentioned design accomplishes the desirability of matching the impedance between the right angled terminals, the connector is somewhat complicated and thereby difficult and costly to manufacture.